The Genome Imaging Shared Resource (GISR) is a new shared resource developed since the last CCSG review. The facility provides tools for cytogenetic analysis of the entire genome as well as specific probes targeted to regions of interest. These include fluorescent in situ hybridization (FISH) with locus specific probes (LSP) generated "in house", specifically designed and labeled based upon the experimental requirements. Spectral Karyotyping (SKY) and whole chromosome painting for human and mouse samples are also part of the service. This facility was initiated in late 2004 with the recruitment of Cristina Montagna from Thomas Ried's laboratory from the NCI. The GISR is not a high-volume facility and, because it was inaugurated only recently, the scope of usage is smaller than for most AECC shared resources. However, this facility provides a very important technology and service to AECC investigators and will play a critical role in the growing genomics and, in particular, epigenetics research activities at the Center.